Dry deposition of
S (sulphur) as sulphate on white marble (natural surfaces) has been measured at
Dayalbagh, a suburban site of semi-arid region of India, in winter season
(December 1999-March 2000). Samples were collected by exposing the white marble
for 24 h and analyzed by Dionex Dx-500 Ion Chromatograph system. Atmospheric concentration
of SO2 was 7.8 ± 2.0 μg m-3 and particulate sulphate was 7.9
± 1.8 μg m-3. The dry deposition of S as sulphate has been found to be
0.19 ± 0.12 mg m-2 h-1. The percentage contribution of the
particulate sulphate (78.9) was higher than that of gas phase (21.1). The calculated
dry deposition velocity (Vd) of particulate sulphate has been
found to be 0.53 ± 0.27 cm s-1. The Vd calculated
by present method is lower than that reported by throughfall method, while Vd
range is comparable to other methods like foliar extraction, micrometeorological
and surrogate methods.